But this DIY rainwater flushing toilet from the UK is about as low-tech and effective as it gets. Using an upstairs balcony to house a barrel cistern; a simple gauze filter system; some charcoal for purification, and then some gravity-fed piping to a downstairs toilet cistern, the system automatically feeds the toilet cistern with rainwater whenever it’s available. When rainwater runs out, the homeowners simply switch back to the mains water.

Love This? Never Miss Another Story.

Thanks for subscribing!

GREAT STORY, RIGHT?

Share it with your friends

77 comments

LOG IN WITH FACEBOOK

OR SIGN IN WITH CARE2

That tee in the pipe looks like it would fail plumbing regulations in the UK. If the mains water pressure in the house fell for any reason (disconnect, stopcock turned off for maintenance elsewhere in the house), non-potable water could enter the potable water system.

I got round that problem by using another route into the cistern: up the overflow pipe. We flush the toilet in our rented house with rainwater without modifying anything:

(continued from my previous comment as it was cutoff halfway)
The best solution to implement this grey water system is to install *two* fill valves on the reservoir of your toilet (one on each side) each with their own float. Using the same ball valve that you already saw in the movie, you can shut off the rain water system if you need to and the city water connection already has a shutoff valve for the toilet where it comes out of the wall. That is a safe setup because water can't back-flow into the drinking water supply.
Ellen M: this setup was actually made in the city, judging from the surroundings in the movie.

Jingli, I am sure that you can find a way to collect rainwater from roofs!
I have several remarks about this movie and the most serious one is that this installation is likely illegal, because it connects the the grey (rain) water to the city drinking water piping. If ever an error is made with the shutoff valves (both opened) then either the tank is going to flood (which is not serious, just a nuisance) or if the city water pressure drops, the house and possibly the neighborhood is receiving rainwater from their taps instead of drinking water!
NOTE that this video is most likely from The Netherlands, not only from the building style but also from the Dutch title in the movie. It does freeze quite a bit in The Netherlands, that is why the vessel and the piping is *plastic* so it does not get damaged when it freezes. You won't be able to flush with rainwater anyway when it freezes (it will be snow or ice) so with the plastic vessel and piping, there is no problem - just that you can't use it for the winter period. (Older systems with metal piping implemented a drain tap, so you could drain the piping before it would freeze)
The best solution to implement this grey water system is to install *two* fill valves on the reservoir of your toilet (one on each side) each with their own float. Using the same ball valve that you already saw in the movie, you can shut off the rain water system if you need to and the city water connection already has a shutoff valve for the toilet wher